偶联剂Si69包覆改性淀粉/炭黑/天然橡胶复合材料的性能研究

采用偶联剂Si69包覆改性的淀粉部分替代炭黑,制备改性淀粉/炭黑/天然橡胶(NR)复合材料,并对其性能进行研究。结果表明:与未改性淀粉/炭黑/NR复合材料相比,偶联剂Si69改性淀粉/炭黑/NR复合材料的加工性能改善,滚动阻力降低,物理性能、压缩疲劳性能和耐热空气老化性能提高,耐磨性能下降;改性淀粉在NR基体中的分散性改善。     

偶联剂Si69原位改性淀粉/NR复合材料的性能研究

采用原位法制备偶联剂Si69改性淀粉/NR复合材料,并研究偶联剂Si69对复合材料性能的影响.结果表明:采用偶联剂Si69对淀粉进行原位改性可以增强淀粉与NR的界面相互作用,改善淀粉在NR中的分散性;偶联剂Si69与淀粉发生了化学作用,并参与了NR的硫化,从而提高复合材料的物理性能.     

偶联剂Si69-纳米氧化锌改性槟榔纤维对天然橡胶复合材料性能的影响

以天然胶乳浸润槟榔纤维,制备天然橡胶(NR)复合材料,研究偶联剂Si69-纳米氧化锌改性槟榔纤维对NR复合材料性能的影响。结果表明:与未改性槟榔纤维的NR复合材料相比,偶联剂Si69-纳米氧化锌改性槟榔纤维的NR复合材料的物理性能、耐溶剂性能和抗湿滑性能改善,剪切模量减小,滚动阻力提高;偶联剂Si69-纳米氧化锌改性槟榔纤维的NR复合材料的综合性能优于偶联剂Si69和纳米氧化锌单独改性槟榔纤维的NR复合材料。     

改性石墨对天然橡胶复合材料导热性能的影响

研究表面活性剂或不同偶联剂对石墨改性效果以及石墨用量对天然橡胶(NR)复合材料物理性能、导热性能及微观结构的影响。结果表明:偶联剂Si69对石墨的改性效果最好,石墨呈现亲油性;与未改性石墨填充NR复合材料相比,偶联剂Si69改性石墨填充NR复合材料中石墨与NR间的界面相容性得到改善,物理性能和导热性能提高;随着偶联剂Si69改性石墨用量的增大,复合材料导热性能提高,物理性能先提高后下降。当改性石墨用量为30份时,复合材料的综合性能较好。     

酚醛树脂改性淀粉/NR复合材料的性能研究

采用间苯二酚-甲醛(RF)树脂改性淀粉,通过乳液共沉法制备淀粉/NR复合材料,研究改性淀粉用量对复合材料性能的影响,并与相同体积分数的炭黑和偶联剂Si69改性的白炭黑填充的NR复合材料进行对比。试验结果表明,RF树脂的加入增强了淀粉与NR之间的交联作用,提高了淀粉/NR复合材料的物理性能;当淀粉用量为20份、经3.6份RF树脂改性后,复合材料的综合性能最佳;随着改性淀粉用量的增大,复合材料的硬度和300%定伸应力增大。当填料体积分数相同时,改性淀粉对NR的补强效果与炭黑接近,且优于白炭黑。     

改性淀粉/天然橡胶复合材料的性能研究

采用硅烷偶联剂Si69对玉米淀粉进行改性,通过机械共混法制备改性玉米淀粉(MCS)/天然橡胶(NR)复合材料。研究了MCS的用量(0份~25份)对MCS/NR复合材料力学性能的影响规律。结果表明:玉米淀粉经过改性后,改善了复合材料的力学性能。复合材料拉伸强度、撕裂强度均在15份时达到最大值,相比未添加MCS的NR,分别提高了60.5%和31%。随MCS用量的增加,硬度呈上升趋势,回弹率变化不明显,耐磨性提高。     

碳酸钙晶须补强天然橡胶的性能研究

采用偶联剂Si69对碳酸钙晶须进行表面处理,研究改性碳酸钙晶须对天然橡胶(NR)性能的影响。结果表明:偶联剂Si69能显著改善碳酸钙晶须的表面性能,提高碳酸钙晶须与NR基体的界面作用,碳酸钙晶须对NR起到明显的补强作用。当改性碳酸钙晶须用量为5份时,复合材料的综合性能最佳。改性碳酸钙晶须的加入使复合材料的热稳定性能得到了一定的提高。     

高性能羧基化多壁碳纳米管/NR复合材料的制备、结构与性能

以超声分散的羧基化多壁碳纳米管(MC)悬浮液填充天然胶乳,采用喷雾干燥法制备MC/NR复合材料,研究偶联剂Si69和KH-550改性对复合材料中填料分散及各项性能的影响.结果表明:喷雾干燥法制备的MC/NR复合材料中碳纳米管分散较好;偶联剂Si69和KH-550与MC表面的羧基发生了化学反应,使其在复合材料中的分散得到进一步改善;当MC用量高于10份时,KH-550改性MC/NR复合材料表现出优异的物理性能和导电性能.     

偶联剂和离子液体改性白炭黑补强天然橡胶性能的研究

研究偶联剂(Si69和B-69)与离子液体溴化1-丁基-3-甲基咪唑(BMIM)单用和并用改性白炭黑补强天然橡胶(NR)的性能。结果表明:与未改性白炭黑补强NR胶料相比,偶联剂Si69、偶联剂B-69和BMIM改性白炭黑补强NR胶料的硫化速率加快,Payne效应减弱,物理性能和耐磨性能提高,滚动阻力降低,偶联剂Si69改性白炭黑的效果优于偶联剂B-69;与偶联剂单用改性白炭黑补强NR胶料相比,偶联剂/BMIM并用改性白炭黑补强NR胶料的硫化速率加快,白炭黑与NR相互作用增强,交联密度增大,物理性能和耐磨性能显著提高,滚动阻力降低,偶联剂B-69/BMIM并用改性白炭黑补强NR胶料的滚动阻力小于偶联剂Si69/BMIM并用改性白炭黑补强NR胶料,抗湿滑性能相差不大;BMIM改性白炭黑补强NR胶料的综合性能最佳。     

淀粉-g-MMA-BA/NR复合材料的制备与性能研究

采用甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)对淀粉进行接枝改性.通过共沉法制备淀粉-g-MMA-BA/NR复合材料,并对复合材料的物理性能和动态力学性能进行研究.结果表明,改性后的淀粉结晶区被破坏,与NR的相容性提高;与NR胶料相比,淀粉-g-MMA-BA/NR复合材料的物理性能和抗湿滑性能有所提高,滚动阻力变化不明显.     

Development and molecular dynamics simulation of green natural rubber composites with modified sisal microcrystalline cellulose

In this study, green composites were prepared using natural rubber (NR) as the matrix and the sisal microcrystalline cellulose (MCC) as the filler. Three modifying agents oleic acid (OA), γ-aminopropyltriethoxylsilane (KH550), and bis-γ-(triethoxysilylpropyl)-tetrasulfide (Si69) were individually tested to modify the MCC to improve the interfacial compatibility of the NR and MCC. Combined with modern instrumental analysis technology and molecular dynamics simulation, the reinforcing effect and microscopic mechanism of modified MCC on NR were analyzed. The structure–activity relationship of NR and MCC composites was further revealed, and the interaction between the two components was clarified. At the same time, the reinforcing and compatibilizing effect of three kinds of modified MCC in NR matrix were also revealed. The results showed that the properties of NR/Mod-MCC composites were better than those of NR/MCC composites, where NR/OA-MCC presented the highest tensile strength, followed by NR/Si69-MCC. In addition, NR/Si69-MCC exhibited higher elongation at break and NR/KH550-MCC exhibited higher vulcanization characteristics. Molecular model systems were constructed through molecular dynamics simulation to investigate the interactions between the three modified cellulose molecules and the NR molecules. OA-cellulose has a better interaction with NR than KH550-cellulose and Si69-cellulose, The simulation results were consistent with the experimental results.     

Effect of NaOH and Si69 treatments on the properties of fly ash/natural rubber composites*

Natural silica in fly ash (FA) particles of 30 and 60 phr were incorporated as reinforcing filler in natural rubber (NR) compounds. Improvements of cure characteristics and mechanical properties of the FA/NR composites were expected by surface treatment of the FA particles, this being carried out using various contents of bis‐(3‐triethoxysilylpropyl) tetrasulfane (Si69), as a chemical silane coupling agent, and sodium hydroxide (NaOH) solution. The results suggested that the Si69 coupling agent was a satisfactory property promoter in the FA/NR composites through C S bonding with rubber molecules and siloxane linkages with FA particles. Using NaOH solution did not improve the mechanical properties of the composites. The mechanical properties of the FA/NR composites appeared to increase at low Si69 concentrations of 2.0–4.0 wt%, but decreased at high Si69 loadings of 6.0–8.0 wt%. The decrease in mechanical properties resulted from a reduction of crosslink density and a formation of flexible polysiloxane from the self‐condensation reaction of the Si69. The presence of Si69 was observed to interfere with the sulphur crosslink formation. No synergetic effect on the properties of the rubber composites was observed when using a mixture of NaOH and Si69. This article recommends concentrations of 2.0–4.0 wt% Si69 to be introduced into the FA/NR composites to achieve the optimum properties. POLYM. COMPOS., 27:30–40, 2006. © 2005 Society of Plastics Engineers     

纳米氧化铝/天然橡胶复合材料的性能研究

采用原位改性纳米氧化铝制备纳米氧化铝/天然橡胶(NR)复合材料,研究纳米氧化铝用量及原位改性时间、偶联剂Si69用量对纳米氧化铝/NR复合材料的物理性能、动态力学性能和导热性能的影响。结果表明:随着纳米氧化铝用量的增大,复合材料的拉伸强度减小,热导率和压缩疲劳温升增大。原位改性可以提高纳米氧化铝与NR之间的界面结合作用。随着原位改性时间的延长或随着偶联剂Si69用量的增大,复合材料的拉伸强度和热导率均先增大后减小,压缩疲劳温升逐渐减小。     

偶联剂对淀粉/丁苯橡胶复合材料性能的影响

采用乳液共混法制备了淀粉/丁苯橡胶(SBR)以及间苯二酚甲醛树脂(RF)改性淀粉/SBR复合材料,考察了偶联剂对2种复合材料硫化特性、力学性能的影响,并用扫描电镜观察了其相态结构。结果表明,各种偶联剂都能在一定程度上提高淀粉/SBR复合材料的拉伸强度和撕裂强度,其中γ-氨基丙基三乙氧基硅烷(KH-550)和N-β(氨基乙基)-γ-氨丙基三甲氧基硅烷(KH-792)的增强效果最为显著;采用RF对淀粉进行改性,RF改性淀粉/SBR复合材料的力学性能较之淀粉/SBR复合材料的力学性能有了进一步提高。橡胶相与淀粉相界面结合的改善是RF改性淀粉/SBR复合材料力学性能提高的主要原因。     

碳酸钙晶须改性对其与天然橡胶复合材料性能的影响

采用Si-69、硬脂酸钠、NDZ101、硬脂酸和十八酸锌5种表面改性剂对碳酸钙晶须进行表面处理,研究了改性碳酸钙晶须对NR性能的影响。结果表明,选用Si-69改性碳酸钙晶须,且用量为5份时,复合材料的力学性能最好,300%定伸应力、拉伸强度、撕裂强度比未改性时分别提高了26.0%,21.1%和22.5%;复合材料的损耗因子(tanδ)最小,比纯胶降低了0.20,玻璃化转变温度(Tg)为-82.8℃,耐寒性最好。     

硅藻土补强NR复合材料的性能研究

以偶联剂Si69为改性剂,制备改性硅藻土/NR复合材料,并对其物理性能、热稳定性和动态力学性能进行研究.结果表明,与未改性硅藻土/NR复合材料相比,改性硅藻土/NR复合材料的物理性能和热稳定性较好,玻璃化温度升高,储能模量和损耗模量相近.